Transparent space between the sections

site: www.hammerstadmaskin.no
I want it to be more like iblog5, but in iblog5 i can not use background image, because it messes up the navigation colours as you see. And the customer want a gradient coloured background
So either i need to know how to fix the nav-bar colours in iblog5 or i need to know how to make a transparent spacing between the sections like on iblog5.